Some time ago I wrote a blogpost about why index might not be used.
While this post seemed to be well received (top link from depesz.com on reddit), it doesn't answer another question – what index to create for given situation.
I'll try to cover this question now.
On 22nd of September, Tom Lane committed patch:
Make EXPLAIN ANALYZE report the numbers of rows rejected by filter steps. This provides information about the numbers of tuples that were visited but not returned by table scans, as well as the numbers of join tuples that were considered and discarded within a join plan node. There is still some discussion going on about the best way to report counts for outer-join situations, but I think most of what's in the patch would not change if we revise that, so I'm going to go ahead and commit it as-is. Documentation changes to follow (they weren't in the submitted patch either). Marko Tiikkaja, reviewed by Marc Cousin, somewhat revised by Tom
Continue reading Waiting for 9.2 – filtered info in explain analyze
I'd like to announce start of new project for PostgreSQL admins – Curo.
On 19th of July, Simon Riggs committed patch:
Cascading replication feature for streaming log-based replication. Standby servers can now have WALSender processes, which can work with either WALReceiver or archive_commands to pass data. Fully updated docs, including new conceptual terms of sending server, upstream and downstream servers. WALSenders terminated when promote to master. Fujii Masao, review, rework and doc rewrite by Simon Riggs
Continue reading Waiting for 9.2 – cascading streaming replication
On 18th of July, Tom Lane committed patch:
Add GET STACKED DIAGNOSTICS plpgsql command to retrieve exception info. This is more SQL-spec-compliant, more easily extensible, and better performing than the old method of inventing special variables. Pavel Stehule, reviewed by Shigeru Hanada and David Wheeler
Continue reading Waiting for 9.2 – Stacked Diagnostics in PL/pgSQL
On 18th of July, Robert Haas committed patch:
Avoid index rebuild for no-rewrite ALTER TABLE .. ALTER TYPE. Noah Misch. Review and minor cosmetic changes by me.
Continue reading Waiting for 9.2 – Avoiding reindexing on alter type of indexed column
Just updated explain.depesz.com site with new functionality – when showing parsed plan, there is new tab “stats". In there you can see some basic statistics of the query, used types of nodes, and tables that were used by it.
There are probably some problems with stats (it's new functionality, so bugs are imminent), but
As usual, some stats need to be added 🙂
Yesterday I talked a bit with David Fetter about improvements in psql. We both would like to get proper stored procedures (with multiple result sets, and transaction control), but since this seems to be too complicated, I thought about what I'd like to have added to psql.
On 6th of July, Robert Haas committed patch:
Add \ir command to psql. \ir is short for "include relative"; when used from a script, the supplied pathname will be interpreted relative to the input file, rather than to the current working directory. Gurjeet Singh, reviewed by Josh Kupershmidt, with substantial further cleanup by me.